just wondering

(I am/was) just wondering.

I only asked (the previous question) out of curiosity. A: "Why do you want to know how much money I have in my savings account?" B: "Oh, no reason really. Just wondering." A: "Don't you think it's a bit rude to ask someone such a personal question?" B: "Sorry, I wasn't trying to pry. I was just wondering."
See also: just
Farlex Dictionary of Idioms.

(I was) just wondering.

a comment made after hearing a response to a previous question. (See examples for typical patterns.) John: Do you always keep your film in the refrigerator? Mary: Yes, why? John: I was just wondering. Bob: Did this cost a lot? Sue: I really don't think you need to know that. Bob: Sorry. Just wondering.
See also: just, wondering
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • (I am/was) just wondering.
  • (I am/was) only wondering.
  • wondering
  • dip into (one's) savings
  • dip into savings
  • accrue
  • accrue to
  • accrue to (something)
  • pay (for something) through (something)
  • pay through